Toboggan

ABSTRACT

A long, flat, thin board, which may be shaped into a toboggan by the ultimate user, is formed by bonding together a pair of polyethylene sheets, the lower of which is ribbed to form runners and the upper of which is ribbed to form transverse braces, the bonded marginal edges of the sheets being arched upwardly at intervals to provide support for a rope-type handrail which is also used as a means for holding the forward end in a reversely curved upright position when it is desired to use the board as a toboggan.

United States Patent 1151 3,666,282 Buening et a]. 1 May 30, 1972 54] TOBOGGAN 2,469,765 5/1949 Fish ..280/18 [72] Inventors: Jerome Buening, Birmingham; Robe" 3,199,887 8/1965 McKelvey ..280/18 M. Paulsen, St. Clair Shores; Clifford A. Roblnette, Fremont, all of Ohio F OR E1GN PATENTS OR APPLICATIONS 487,166 10/1952 Canada ..280/l8 Primary Examiner-Benjamin Hersh Assistant ExaminerWinston H. Douglas Attorney-Harness, Dickey & Pierce [57] ABSTRACT A long, flat, thin board, which may be shaped into a toboggan by the ultimate user, is formed by bonding together a pair of polyethylene sheets, the lower of which is ribbed to form runners and the upper of which is ribbed to form transverse braces, the bonded marginal edges of the sheets being arched upwardly at intervals to provide support for a rope-type handrail which is also used as a means for holding the forward end in a reversely curved upright position when it is desired to use the board as a toboggan.

12 Claims, 6 Drawing Figures I i 4/ J I ll TOBOGGAN BACKGROUND OF THE INVENTION As is well known, toboggans normally have a rigid, upwardly extending, reversely curved, forward wall section that blends into the long, flat, thin main body of the toboggan. The upper portion of the body serves as a seat for the toboggan riders and the bottom portion engages the surface over which the toboggan is moving. Toboggans with the rigid forward end are, of course, somewhat awkward to stow and are expensive to ship, particularly in large numbers, because of the volume of space occupied by the forward end. Normally, the toboggans are made of wood and many sledding enthusiasts apply surface treatmenm such as waxing to the bottom of the toboggan in order to reduce its friction and increase the speed that can be attained. It is desirable also that the main body portion of the toboggan have adequate strength to resist fracture and yet be flexible enough to glide over irregularities in the surface being traversed, a combination somewhat difficult to achieve with ordinary wood constructions.

BRIEF SUMMARY OF THE INVENTION It is a purpose of the invention to provide a long, flat, thin board which may be shaped when desired into a toboggan. It is also a specific purpose of the invention to provide a toboggan construction having a lower coefficient of friction than conventional constructions and having a better flexibility to strength ratio than is normally achieved with conventional materials. More generally, it is a purpose of the invention to provide a light weight, readily manufactured, strong and slightly flexible board structure composed of interconnected ribbed sheets of synthetic resinous material.

The invention accomplishes the foregoing purposes by means of a board that has upper and lower sections integrated together to produce a unitary structure. The upper and lower sheets are ribbed in an appropriate manner to give the desired functional characteristics along with strength and flexibility. When used as a toboggan, the ribs are positioned in such a manner as to permit the forward end of the board to be curved by hand from a flat position to the erect buffer position or vice versa. Preferably, the sheets are formed of polyethylene resin which retains its flexibility and is very slippery even at very low temperature.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the invention as embodied in a toboggan and shows the toboggan in position for use;

FIG. 2 is a perspective view of the bottom face of the tobogg FIG. 3 is a perspective view of the toboggan of FIGS. 1 and 2 with the side ropes removed and the forward end in the flat position;

FIG. 4 is a cross section along the line 4-4 of FIG. 1 and shows the transverse bracing ribs formed in the upper sheet;

FIG. 5 is a cross section along the line 5-5 of FIG. 1 and shows the longitudinal runners in the bottom sheet as well as a rope supporting arch formed in the margin of the toboggan body; and

FIG. 6 is a cross section along the line 6-6 of FIG. 1 and shows the marginal side rail as well as bottom runners in the structure.

DETAILED DESCRIPTION OF THE INVENTION The toboggan 1 in its conventional aspects has a long, flat, thin board section 3 which serves as the main body of the toboggan upon which the passengers are seated. At the forward end of the body portion 3 is the upwardly and reversely curved front wall section 5 extending around the longitudinal side edges of the main body 3 and across the terminating end of the front wall 5 is a rope 7 which is used by some as a flexible handgrip or rail.

In accordance with the present invention, the main body 3 and the front wall 5 are formed by a pair of sheets that are secured together, as by bonding or heat sealing, to form a unitary or integral structure, the upper sheet being designated by the reference number 9 and the lower sheet being the reference number 11. These sheets are preferably formed from a suitable synthetic plastic material such as polyethylene resin which is formed and cured in accordance with known forming and curing techniques. Polyethylene has the desired property of a low coefiicient of friction which it retains along with its flexibility at the very low temperatures that would be encountered in use of a toboggan. The slipperiness of the polyethylene material therefore eliminates the need for waxing because of its own characteristic low friction. Additionally, the polyethylene is very tough and fracture resistant while at the same time being flexible enough to enable the body 3 of the toboggan to ride over surface irregularities.

The natural properties of the polyethylene material are enhanced by the ribbed structure illustrated which also has the advantage of providing an attractive appearance to the toboggan. Thus, the bottom sheet 11 has outwardly extending ribs 13, 15, and 17 embossed therein and located adjacent the longitudinal sides and midplane of the main body 3. Intermediate the ribs 13 and 15 are a pair of narrower ribs 19 while between the ribs 15 and 17 are the narrower ribs 21. The upper sheet 9 has a raised rail section 23 which is formed by longitudinal side ribs 25 and end ribs 27 which merge with and form transverse extensions of the side ribs. Transverse ribs 29 extend between and blend into the side ribs 25 and are preferably somewhat shallower and of a slightly rounded configuration at the corners inasmuch as they are located within the seating area that is defined by the outer rail 23. The ribs define individual seating areas and can serve to hold cushions (not shown) in position. The combination of rail 23 and transverse ribs 29 serves to substantially strengthen the initially flat sheet from which the upper section 9 is formed while still permitting flexibility around axes that extend transversely to the length of the toboggan. As can be seen in FIG. 3, the forward end rail 27 section of the marginal rail 23 marks substantially the line at which the main body 3 is reversely curved to turn into the forward wall section 5. Neither the longitudinal ribs 25 or the various ribs 13, 15, 17, 19 and 21 on the bottom sheet 11 extend any substantial distance into the section 5. However, there may be several additional transverse ribs 31 corresponding in shape and length to the rib 27 located within the section 5. With this reduction or elimination of ribs the section 5 can be readily curved about a transverse axis from a flat or substantially flat condition of FIG. 3 into the curved condition of FIGS. 1 and 2. Alternatively, it is possible to form the front end portion from only one of the sheets so that it is the main body 3 alone that has a two sheet construction.

The various ribs that have been referred to are located spaced distances within the outermost edges of the upper and lower sheets 9 and 11 thereby leaving marginal flanges or edge sections 33 and 35 along the longitudinal side edges of the sheet and marginal end sections 36 and 38 along the front and rear edges of the sheets which blend together and extend around the entire periphery of the sheets. The marginal edges or sections 33, 35, 36, and 38 are formed by flat outer parts of the upper and lower sheets which are in surface to surface contact which along with other contacting surfaces of the upper and lower sheets are united together in a tight, permanent joint by suitable means preferably by the process described in US. Pat. Nos. 3,242,245 and 3,250,660. As a result of being secured to each other, the two sheets form a unified, integrated structure in which the lower side has the hollow longitudinal ribs or runners shown in FIG. 2 and the upper side has the hollow bracing rib structure shown in FIGS. 1 and 3.

The margins 33 and 35 are deformed into transversely aligned raised bosses or arch sections 37, 39, and 41 as indicated best in FIGS. 1 and 3. Opposite side walls of the arch sections are provided with longitudinally aligned holes 43 through which the rope 7 passes, the rope also passing through holes 45 adjacent the forward end of the section 5 in the flat margin thereof.

The rope 7 is preferably used to hold the forward section 5 in the curved condition of P108. 1 and 2, though a separate rope or ropes may be used if desired. In doing this, a knot 47 is tied in one end of the rope 7 and the rope is threaded through the arches 37 and 39 and 41, another knot (not shown) being formed in the rope on the inside of the arch 41 on the rail 33 side of the toboggan. The rope is then threaded through one of the holes 45 and across the back or lower sheet 11 as seen at 51 and then through the second hole 45 into the arch 41 on the opposite side of the toboggan, another knot being formed in the rope inside of the arch 41 after the rope has been pulled tight enough to hold the section 5 in the desired curved condition of FIGS. 1 and 2. Thereafter, the rope 7 is threaded through the remaining arches 39 and 37 and a final knot 53 is formed in it on the outside of the last arch 37 to hold the rope in a taut condition. If it is desired by the user of the toboggan to stow it in flat condition, this can be done by untying the knots at the arches 37 and 41 on one side thereby releasing the force that holds the section 5 in the curved condition permitting it to be unfolded to a substantially flat condition as an extension of the body 3.

As a toboggan, it will be noted that the bottom runner structure of FIG. 3, including the pointed, tapered ends of the ribs, provides an optimum surface for sliding which helps to maintain the movement of the toboggan in a longitudinal direction and resists side slippage to some degree. The polyethylene material has a non-directional grain and retains its resilience and slipperiness at low temperatures, requires no screws, slats, varnish, or waxing, has a minimum tendency to warp, and with the construction shown enables the front end 5 to be flat or curved at the option of the shipper or user. The polyethylene toboggan is capable of permanently sliding faster down an incline than toboggans made of waxed wood, metal, or other plastics and because of its self lubrication characteristic enables the toboggan to be used on partially snow covered slopes or even slopes covered with grass or synthetic sliding means. When formed as indicated the toboggan has superior resistance to impact or bend fracturing and to marring than wood, is lighter in weight, and more readily shipped and manufactured.

While the structure illustrated has a most fruitful application as a toboggan structure, it will be apparent that other usages may be made of structures embodying limited concepts or features of the invention, such as a structure which omits the front end 5 or also has a rear end corresponding to 5, or which has a continuous upraised siderail corresponding to a continuous arch structure, etc. which structures could be used in litters, stretchers, pallets, etc. Thus, the invention is not limited to the precise structure that is illustrated and described.

We claim:

1. A toboggan or the like comprising a long, thin, substantially flat board having a main body portion with runner and seating surfaces and a front end portion integral with the main body portion which forms an operative front wall for the toboggan, said board comprising upper and lower sheets, the upper sheet having raised marginal side ribs to define side rails, said sheets having marginal flanges; one of said sheets having additional ribs formed therein of substantially U- shaped cross section and spaced from the other sheet, the marginal flanges of said sheets being secured together to unitize the sheets.

2. A toboggan according to claim 1, said sheets being composed of polyethylene.

3. A toboggan according to claim 1, said additional ribs being formed in said upper sheet and extending transversely to said board.

4. A toboggan according to claim 1, said additional ribs being formed in said lower sheet and extending longitudinally of said board.

5. A toboggan according to claim 4, further provided with transversely extending ribs in said upper sheet spaced from said lower sheet.

6. A toboggan according to claim 5, said sheets being composed of polyethylene, the contacting surfaces of said sheets being united in a tight permanent joint so that the two sheets form a unified integrated structure.

7. A toboggan according to claim 1, said front end portion being bendable into and out of a position in which it forms said operative front wall.

8. A toboggan according to claim 7, said front end and main body portions including connection means whereby a connection may be made between the portions to hold the front end portion in an operative front wall position.

9. A toboggan according to claim 1, said side rails comprising raised ribs in said upper sheet extending around said main body portion.

10. A toboggan according to claim 9, further provided with a plurality of arches formed in said side rail ribs, and rope extending through said arches to form handle means.

11. A toboggan according to claim 10, portions of said rope serving to hold said front end portion in position as an operative front wall.

12. A toboggan according to claim 1, further provided with handle means mounted adjacent to said raised marginal side ribs. 

1. A toboggan or the like comprising a long, thin, substantially flat board having a main body portion with runner and seating surfaces and a front end portion integral with the main body portion which forms an operative front wall for the toboggan, said board comprising upper and lower sheets, the upper sheet having raised marginal side ribs to define side rails, said sheets having marginal flanges; one of said sheets having additional ribs formed therein of substantially U-shaped cross section and spaced from the other sheet, the marginal flanges of said sheets being secured together to unitize the sheets.
 2. A toboggan according to claim 1, said sheets being composed of polyethylene.
 3. A toboggan according to claim 1, said additional ribs being formed in said upper sheet and extending transversely to said board.
 4. A toboggan according to claim 1, said additional ribs being formed in said lower sheet and extending longitudinally of said board.
 5. A toboggan according to claim 4, further provided with transversely extending ribs in said upper sheet spaced from said lower sheet.
 6. A toboggan according to claim 5, said sheets being composed of polyethylene, the contacting surfaces of said sheets being united in a tight permanent joint so that the two sheets form a unified integrated structure.
 7. A toboggan according to claim 1, said front end portion being bendable into and out of a position in which it forms said operative front wall.
 8. A toboggan according to claim 7, said front end and main body portions including connection means whereby a connection may be made between the portions to hold the front end portion in an operative front wall position.
 9. A toboggan according to claim 1, said side rails comprising raised ribs in said upper sheet extending around said main body portion.
 10. A toboggan according to claim 9, further provided with a plurality of arches formed in said side rail ribs, and rope extending through said arches to form handle means.
 11. A toboggan according to claim 10, portions of said rope serving to hold said front end portion in position as an operative front wall.
 12. A toboggan according to claim 1, further provided with handle means mounted adjacent to said raised marginal side ribs. 